What is the Best Material to Put Under Pavers?

Introduction

Pavers are a popular choice for creating beautiful and durable outdoor spaces such as patios, driveways, and walkways. However, the longevity and stability of a paver installation largely depend on what lies beneath them. The selection of the right material for the base and sub-base is crucial for ensuring that your pavers remain level and stable over time. In this article, we will explore the best materials to use under pavers, their benefits, and considerations for making the right choice.

Importance of a Proper Base

Before diving into the specific materials, it’s essential to understand why a proper base is so important. The base provides a stable foundation that supports the pavers and helps distribute weight evenly, preventing them from shifting, settling, or cracking. A well-constructed base also aids in drainage, preventing water from pooling under the pavers and causing erosion or frost heave.

Best Materials for Paver Bases

1. Crushed Stone
   • Description: Crushed stone is one of the most popular base materials for pavers. It is made from a variety of stone types, including granite, limestone, and trap rock.
   • Benefits:
     • Excellent compaction properties
     • Provides a strong and stable base
     • Good drainage capabilities
   • Considerations: The size of the crushed stone can vary, but a commonly used size for paver bases is 3/4-inch. It’s important to compact the crushed stone thoroughly to prevent future settling.
2. Gravel
   • Description: Gravel is another common base material. It consists of small stones and can be either naturally rounded or crushed.
   • Benefits:
     • Good drainage properties
     • Cost-effective
     • Readily available
   • Considerations: Gravel needs to be compacted well, and the depth of the gravel layer is critical for stability.
3. Sand
   • Description: Sand is typically used as a bedding layer directly beneath the pavers. It provides a smooth, even surface for the pavers to rest on.
   • Benefits:
     • Easy to level and work with
     • Provides a cushion to prevent pavers from cracking
   • Considerations: While sand alone is not used as a base, it is crucial as a bedding material. Polymeric sand can be used in joints to help lock the pavers in place and prevent weed growth.
4. Geotextile Fabric
   • Description: Geotextile fabric is a synthetic material used to separate different layers of base materials and prevent the mixing of soil and aggregate.
   • Benefits:
     • Enhances stability by preventing soil movement
     • Improves drainage
     • Extends the life of the paver installation
   • Considerations: It’s important to install the fabric correctly to ensure its effectiveness.
5. Recycled Concrete Aggregate (RCA)
   • Description: RCA is made from crushed and processed concrete debris from demolished structures.
   • Benefits:
     • Environmentally friendly option
     • Comparable performance to natural aggregates
     • Often more affordable
   • Considerations: The quality of RCA can vary, so it’s important to source it from a reputable supplier.

Steps to Prepare a Paver Base

1. Excavation: Begin by excavating the area to the appropriate depth. The depth will depend on the type of pavers, the expected load, and the local climate. Typically, the excavation depth ranges from 6 to 12 inches.
2. Sub-Base Layer: Lay the sub-base material (such as crushed stone or gravel) in layers, compacting each layer thoroughly with a plate compactor. The sub-base should be 4 to 8 inches deep, depending on the application.
3. Geotextile Fabric: If using geotextile fabric, lay it over the compacted sub-base to prevent soil migration and improve stability.
4. Bedding Layer: Spread a 1-inch layer of sand over the geotextile fabric or directly over the compacted sub-base. Use a screed board to level the sand.
5. Laying the Pavers: Begin placing the pavers in your desired pattern, ensuring they are level and properly aligned.
6. Joint Filling: Once the pavers are laid, fill the joints with polymeric sand or regular sand. Compact the pavers again to settle the sand into the joints.
7. Final Compaction: Perform a final compaction to ensure all pavers are firmly set.

Conclusion

Choosing the right material for the base of your paver project is crucial for its longevity and performance. Crushed stone, gravel, and sand are the most commonly used materials, each offering specific benefits. Incorporating geotextile fabric can further enhance the stability and lifespan of your installation. By following proper preparation and installation steps, you can create a durable and attractive paver surface that will stand the test of time.

FAQs

Q: Can I use plain soil as a base for pavers? A: No, plain soil is not recommended as it does not provide the necessary stability and drainage. It can lead to settling and shifting of the pavers over time.

Q: How deep should the base for pavers be? A: The depth of the base depends on the type of pavers and the expected load. For pedestrian areas, a base depth of 4-6 inches is typically sufficient. For driveways, a depth of 8-12 inches is recommended.

Q: Is it necessary to use geotextile fabric under pavers? A: While not always necessary, geotextile fabric can improve the stability and longevity of your paver installation by preventing soil migration and enhancing drainage.

Q: How do I know if I have compacted the base material enough? A: Proper compaction is achieved when the base material does not shift or move underfoot. Using a plate compactor, compact each layer of base material thoroughly before adding the next layer.

Q: Can recycled concrete aggregate (RCA) be used for paver bases? A: Yes, RCA can be an effective and environmentally friendly option for paver bases, provided it is sourced from a reputable supplier and meets the necessary specifications for stability and drainage.

Q: What type of sand should be used for the bedding layer? A: Coarse, well-graded sand, often referred to as concrete sand, is ideal for the bedding layer. Avoid using fine sand, as it can lead to shifting and settling of the pavers.

By selecting the right materials and following proper installation techniques, you can ensure a durable and aesthetically pleasing paver project that will enhance your outdoor space for years to come.